Damper-regulator.



PATENTED- APR. "26, 1904.

E. A. PRAH'L. DAMP-ER REGULATOR.

APPLIOATION IIrmlyhxlw.4 ze, y190:4.

N0 MODEL.

. y @Hangul UNITEDY STATES Patented April 26, 190.4.

PATENT OFFICE.

DANIPER-REGULATOR.

SPECIFICATION forming part of Letters Patent No. 758,471, dated April 26, 1904.

i Application led January 28, 1903. -Serial No. 140.909. (No model.) i

To a/ whom 2S may concern,.-

Be it known that I, EDWARD A. PRAHL, a citizen of the United States, residing at Philadelphia, in the county of Philadelphia and State of Pennsylvania, have invented new and useful Improvements in Damper-Regulators, of which thefollowing is a specification.

This invention relates to draft regulators or dampers for steam-boiler furnaces;l and the object thereof is to provide an eiiicient mechanism for automatically controlling the draft within a boiler-furnace.

The invention consists in providing a theri mostat controlled by the water Within the boiler and carrying adjustable means for opening the smoke-flue when the water reaches a determined temperature.

The invention further consists in the details i of .construction and combination of parts to be referred to hereinafter, and illustrated'in the accompanying drawings, forming` a part of this specification, and in Which- Figure 1 represents a sideelevation of a draft-regulator constructed in accordance with my invention. Figl 2 represents a vertical transverse sectional View through the mer- Icury-cup. Fig. 3 is a vertical longitudinal sectional view through the mercury-cup and its casing.

Referring to the drawings by numerals of reference, l designates a Wall of aboiler, and removably secured thereto is a casing 2, provided With a stem or restricted portion which is threaded into the wall of the boiler, the opposite end being in the form of a cup, the upper end of which is threaded internally to receive the externally-threaded portion of a mercury-cup 3. A

From the foregoing it will be understood that the improved draft-regulator is to be used with any steam-boiler furnace, including a smoke-Hue, and as these furnaces structurally are well understood a complete furnace has vnot been illustrated in the accompanying drawof, through which projects the lower end of a vertically-arranged threaded tube 5, carrying at its upper extremity a cup or receptacle 6.

The tube 5 extends down to av point adjacent tothe bottom of the cup 3 and serves as a means for introducing the mercury or other expansible fluid from the receptacle 6 into the cup 3. I/Vithin and extending the entire length of the tube 5 is a vertically-arranged ,rod 7 projecting above the receptacle 6`and carrying at its upper extremity a horizontal bar 8, which constitutes the actuating means for opening the door Aof .tlie'smoke-flue, as will be presently explained. Arranged atsuitable intervals on the tube 5 are supports or brackets 9 and 10, having vertical openings at their free ends, through which projects a vertical supporting-bar l1, adjustably secured in said openings by means of set-screws 12, adapted to bind against and holdthe rod in adjusted position. Nearthe upper extremity of the rod 1 1 is a pulley 13, alining with asimilar pulley 14: intermediate the ends of the rod 11 and preferably arranged near the center vof the said rod.k These pulleys are disposed on opposite sides'of the actuating-bar 8, carried by the rod 7, and a chain or flexible connection l5. is terminally pansion of the liquid within the cup 3. A'

partition 2O is formed in the stem or restricted portion of the casing 2, so that a circulation will be set up therein as the water iows into and out of the saine.

i All of the parts being assembled, the operation is described as follows: Assuming that theV rod 11 has been properly adjusted, the door will remain closed until the water reaches secured to one end of the said bar 8 and passes the temperature above a. determined degree,

-when the liquid Vwithin the cup willv be vexpanded and forced up into thevtube 5. This willcause the rod 7 to move upward, carrying with it the bar 8. As the bar 8 moves upward apull Will be exertedupon the flexi- IOC opened and permit the draft to be established through the smoke-flue instead of under the fire-box of the furnace. When the draft is cut off from the fire-box, the fire will rapidly cool, and as soon as the temperature of the water has decreased the resultant cooling of the liquid within the cup 3 will cause it to contract, thereby allowing the rod 7 to lower to its normal position, and as the force eX- erted by the rod 8 will be relieved the door 16 will swing back into a closed position by its own weight.

By reference to Figs; 2 and 3 it will be observed that the rod 7 is arranged to float in the mercury and is directly engaged and positively actuated thereby. This rod is slightly less in diameter than the interior diameter of the tube 5, and this construction avoids the friction of a piston, no limit being imposed to the expansion of the mercury, and the latter is free to expand even if the damper should refuse to open, thus avoiding the rupture of any of the parts. A further most important advantage practically resulting from this differentiation in diameter between the tube 5 and rod 7 is that should the damper stick the mercury would be forced to a great height in the tube, affording additional power to open the damper with no danger of injury to the parts. The space between the mercury and the top of the cup is charged with a suitable volatile material, such as ether, to form a gas and assist in the displacement of the mercury from the cup in the tube by the heat from the boiler. The depending end of the tube which extends into the cup forms a restricted channel or passage for the mercury, so that a comparatively small displacement of the mercury within the cup will effect a relatively large vertical movement of the rod.

By adjusting the rod 11 vertically in the brackets or supports 10 the device can be regulated to actuate the door when the water reaches different degrees of temperature, and, if desired, a scale can be placed upon the rod 11 to guide the operator in making proper adjustments. By` reference to F ig. 1 it will be observed that the vertical adjustment of the rod 11 will cause a certain amount of slack to be effected in the connection 15 or take up the slack in the latter, so that the operating device may be set for actuation by different degrees of temperature.

In order to facilitate the assemblage and detachment of the cup 3, an angular head 21 is formed on the top of the said cup, so that the latter can be readily applied or removed from the casing Q.

If from excessive heat the mercury passes up through the tube the escape thereof will be prevented by the receptacle 6, which constitutes a safety as well as a receiving receptacle for the mercury or expansive Huid disposed in the cup 3.

It will be obvious that a device constructed in accordance with the above-described invention will be effective and durable and will readily perform the service for which it is intended.

Having thus described my invention, what I claim as new is- 1. In a draft-regulator, the combination with a receptacle adapted to contain mercury, of an elongated tube forming an outlet from said receptacle, an elongated rod adapted to be movably floated in said tube and spaced sufficiently from the latter to permit the passage of mercury between it and the tube, a damper, and a connection between the damper and rod.

2. In a draft regulator, the combination with a receptacle adapted to contain mercury, of an elongated tube forming an outlet from said receptacle, an elongated rod adapted to be movably iioated in said tube and spaced sufficiently from the latter to permit the passage of mercury between it and the tube, an arm carried hy the said rod, a vertically-adjustable rod connected to one side of the tube and carrying pulleys, a damper, and a flexible connection secured to the damper and passing over the said pulleys and attached to the rod in the tube.

3. In a draft-regulator, the combination with a steam-boiler furnace, including a smokeflue and damper for the latter, of a receptacle connected to the boiler and having an expansible liquid therein supporting a volatile material, an elongated tube forming an outlet from said receptacle, an elongated rod adapted to be movably oated in said tube and spaced suficientlyfrom the latter to permit the passage of mercury between it and said tube, a'

damper, and a connection between said damper and rod.

4. In a draft-regulator, the combination with a steam-boiler and furnace, of a damper associated with the smoke-fiueof the furnace, a casing having a restricted stem secured to the boiler, and a cup provided with a receptacle adapted to contain mercury, an elongated tube attached to and forming an outlet from said receptacle, a receptacle on the upper end of the tube, an elongated rod movably iioated in said tube and spaced sufficiently from the latter to permit the passage of mercury between it and the tube, and a connection between said damper and rod.

In testimony whereof I aiiix my signature in presence of two witnesses.

. EDW. A. PRAHL. Witnesses:

THOMAS F. Gnoss, NORMAN J. SMITH.

IIO 

